Posted almost 6 years ago. Visible to the public.

Testing terminal output with RSpec

When testing Ruby code that prints something to the terminal, you can test that output.
Since RSpec 3.0 there is a very convenient way to do that.

Anything that writes to stdout (like puts or print) can be captured like this:

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expect { something }.to output("hello\n").to_stdout

Testing stderr works in a similar fashion:

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expect { something }.to output("something went wrogn\n").to_stderr

Hint: Use heredoc to test multi-line output.

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expect { something }.to output(<<-MESSAGE.strip_heredoc).to_stdout Dear Bob, greetings! Love, Alice MESSAGE

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Owner of this card:

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Arne Hartherz
Last edit:
almost 6 years ago
by Arne Hartherz
Keywords:
console
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License for source code
Posted by Arne Hartherz to makandra dev
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